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[[!template id=gitbranch branch=smcv/unescaped-meta author="[[Simon_McVittie|smcv]]"]]
[[!tag patch]]
(Warning: this branch has not been tested thoroughly.)
While discussing the [[plugins/meta]] plugin on IRC, Joey pointed out that
it stores most meta fields unescaped, but 'title', 'guid' and 'description'
are special-cased and stored escaped (with numeric XML/HTML entities). This
is to avoid emitting markup in the `<title>` of a HTML page, or in an RSS/Atom
feed, neither of which are subject to the [[plugins/htmlscrubber]].
However, having the meta fields "partially escaped" like this is somewhat
error-prone. Joey suggested that perhaps everything should be stored
unescaped, and the escaping should be done on output; this branch
implements that.
Points of extra subtlety:
* The title given to the [[plugins/search]] plugin was previously HTML;
now it's plain text, potentially containing markup characters. I suspect
that that's what Xapian wants anyway (which is why I didn't change it),
but I could be wrong...
> AFAICS, this if anything, fixes a bug, xapian definitely expects
> unescaped text here. --[[Joey]]
* Page descriptions in the HTML `<head>` were previously double-escaped:
the description was stored escaped with numeric entities, then that was
output with a second layer of escaping! In this branch, I just emit
the page description escaped once, as was presumably the intention.
* It's safe to apply this change to a wiki and neglect to rebuild it
(assuming I implemented it correctly!), but until the wiki is rebuilt,
titles, descriptions and GUIDs for unchanged pages will appear
double-escaped on any page that inlines them in `quick=yes` mode, and
is rebuilt for some other reason. The failure mode is too much escaping
rather than too little, so it shouldn't be a security problem.
* Reverting this change, if applied, is more dangerous; until the wiki is
rebuilt, any titles, descriptions and GUIDs on unchanged pages that
contained markup could appear unescaped on any page that inlines them
in `quick=yes` mode, and is rebuilt for some other reason. The failure
mode here would be too little escaping, i.e. cross-site scripting.
[[!tag done]]
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